Oral health is maintained by a healthy microbiome, which can be monitored by state-of-the art diagnostics. Therefore, this study evaluated the presence and quantity of ten oral disease-associated taxa (P. gingivalis, T. forsythia, T. denticola, F. nucleatum, C. rectus, P. intermedia, A. actinomycetemcomitans, S. mutans, S. sobrinus, oral associated Lactobacilli) in saliva and their clinical status association in 214 individuals. Upon clinical examination, study subjects were grouped into healthy, caries and periodontitis and their saliva was collected. A highly specific point-of-care compatible dual color qPCR assay was developed and used to study the above-mentioned bacteria of interest in the collected saliva. Assay performance was compared to a commercially available microbial reference test. Eight out of ten taxa that were investigated during this study were strong discriminators between the periodontitis and healthy groups: C. rectus, T. forsythia, P. gingivalis, S. mutans, F. nucleatum, T. denticola, P. intermedia and oral Lactobacilli (p < 0.05). Significant differentiation between the periodontitis and caries group microbiome was only shown for S. mutans (p < 0.05). A clear distinction between oral health and disease was enabled by the analysis of quantitative qPCR data of target taxa levels in saliva.

This study investigated the potential of salivary bacterial and protein markers for evaluating the disease status in healthy individuals or patients with gingivitis or caries. Saliva samples from caries- and gingivitis-free individuals (n = 18), patients with gingivitis (n = 17), or patients with deep caries lesions (n = 38) were collected and analyzed for 44 candidate biomarkers (cytokines, chemokines, growth factors, matrix metalloproteinases, a metallopeptidase inhibitor, proteolytic enzymes, and selected oral bacteria). The resulting data were subjected to principal component analysis and used as a training set for random forest (RF) modeling. This computational analysis revealed four biomarkers (IL-4, IL-13, IL-2-RA, and eotaxin/CCL11) to be of high importance for the correct depiction of caries in 37 of 38 patients. The RF model was then used to classify 10 subjects (five caries-/gingivitis-free and five with caries), who were followed over a period of six months. The results were compared to the clinical assessments of dental specialists, revealing a high correlation between the RF prediction and the clinical classification. Due to the superior sensitivity of the RF model, there was a divergence in the prediction of two caries and four caries-/gingivitis-free subjects. These findings suggest IL-4, IL-13, IL-2-RA, and eotaxin/CCL11 as potential salivary biomarkers for identifying noninvasive caries. Furthermore, we suggest a potential association between JAK/STAT signaling and dental caries onset and progression.

Besides dental plaque and external staining, toothbrushing can also remove some sound exposed dentin, the so-called 'abrasive dentine wear'. Abrasive dentine wear is a multifactorial process and could be affected by factors such as the abrasivity of the toothpaste, the applied brushing force and frequency of toothbrushing and the mechanical properties of the toothbrush, to name a few. 1

The aim of this study was to investigate margin integrity of Class V composite restorations in demineralized and sound enamel after bonding with different etch-and-rinse and self-etch adhesive systems. Out of a total of 60 specimens from bovine incisors, 30 specimens were demineralized (21 days, acid buffer, pH 4.95) to create artificial enamel lesions. Circular Class V cavities were prepared in all 60 specimens and treated with either an unfilled etch-and-rinse adhesive (Syntac Classic; Ivoclar Vivadent), a filled etch-and-rinse adhesive (Optibond FL; Kerr), or a self-etch adhesive (iBond Self Etch; Heraeus) (n = 10 per group). The cavities were restored with a nanofilled resin composite and thermocycled (5000×, 5-55°C). Scanning electron microscopy was used to evaluate margin integrity of the composite restorations, and the percentage of continuous margin was statistically analyzed (= 0.05). Demineralized enamel led to a significantly lower margin integrity when the self-etch adhesive iBond Self Etch was applied, but did not affect margin integrity when the etch-and-rinse adhesives Optibond FL (filled) or Syntac Classic (unfilled) were used. No significant differences in margin integrity in sound and demineralized enamel were observed between the different adhesives. Demineralized enamel reduces margin integrity of composite restorations when bonded with a self-etch adhesive, but does not affect margin integrity when an etch-and-rinse approach is used.

Objectives: This in vitro study aimed to evaluate and compare the effect of two different bioactive glasses, a hydroxyapatite-containing, fluoride-free toothpaste (HTP) and a fluoride toothpaste (FTP) on the remineralization behavior of initial caries lesions. Materials and Methods: A total of 100 bovine enamel samples were randomly allocated to five groups of 20 samples each: NC = negative control group (artificial saliva); HTP = HTP group (Karex); FTP = FTP group (Elmex caries protection, 1,400 ppm); FTP + BG_nano = FTP followed by Actimins bioactive glass; FTP + BG_amorph = FTP followed by Schott bioactive glass. Radiographic documentation (advanced transversal microradiography; aTMR) was applied before and after all samples were exposed to a demineralizing gel for 10 days. Over a period of 28 days, samples were covered twice a day (every 12 h) with a toothpaste slurry of the respective test group or with artificial saliva in NC for 60 s and brushed with 15 brushing strokes. Samples in FTP + BG_nano and FTP + BG_amorph were additionally treated with the respective bioactive glass slurry for 30 s after brushing with the FTP. In the meantime, all samples were stored in artificial saliva. After 28 days, the structure of all samples was assessed again using aTMR and compared to the values measured after demineralization. The statistical evaluation of the integrated mineral loss was performed using Kruskal-Wallis test followed by a post hoc Conover test. Results: The FTP revealed the significantly highest increase of mineral content while the HTP showed the significantly lowest remineralization. Compared to artificial saliva, the use of the HTP or the combined application of FTP followed by bioactive glasses (FTP + BG_nano and FTP + BG_amorph) showed no significant remineralization. Conclusion: Under remineralizing in vitro conditions, brushing with 1,400 ppm FTP induced significantly more remineralization compared to storage in artificial saliva. The additional administration of both bioactive glasses as well as the substitutional brushing with an HTP resulted in significantly less remineralization compared to brushing with 1,400 ppm FTP.